Wow! Around here, 50 is a mild night. If we dressed like that, the caption of the picture would be "what is this?"
Around here 50 is freezing. Did a game in Prescott this year and the temperature was hovering right around 45 to 50, it was cold. My hands were ice by the end of the game.
However as this is Arizona, none of our crew has anything long sleeved. I don't think anyone even produces a long-sleeved shirt with AIA logo and position placard on the back.
I still have all my cold gear from when I was in Ohio and I have been told (but not officially) that we can wear long sleeved black shirts under our short-sleeved shirt, but personally I think that would look really bad.